POLYMERS & POLYMER COMPOSITES
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2020
·
IF 1.023
Yawen Fang,Yanbin Wang,Yongchao Li,Huang Yu,Changlong Zhuang,Zhonglin Luo,Zicheng Fan,Biaobing Wang
A series of novel ternary conductive composites have been prepared by incorporating functionalized multiwalled carbon nanotubes (FMWCNTs) into the binary composites of poly(amide-imide) (PAI) and poly(o-methoxyaniline) (POMA) to further improve the conductivity of PAI composites. With increasing the weight ratio of FMWCNTs, the conductivity of PAI/POMA/FMWCNTs ternary composites has been significantly enhanced from 10−3 S m−1 to 90 S m−1, much higher than that of the sum of PAI/POMA and PAI/FMWCNTs binary composites. The enhanced conductivity is mainly ascribed from a much more intensive conductive network formed in the PAI/POMA/FMWCNTs ternary composites. It is found that the N–H bending of amide group in the Fourier transform infrared spectrometry spectra is observed at 3298 cm−1 for PAI, 3296 cm−1 for PAI/POMA binary composites, and further blue shifted to 3292 cm−1 for PAI/POMA/FMWCNTs ternary composites. Moreover, the glass transition temperature has been increased from 82.5°C to 117.7°C. These results suggested that the hydrogen bonding interaction has been strengthened among PAI, POMA, and FMWCNTs, which is useful for dispersion of condcutive fillers into the polymer matrix.
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高影响因子
POLYMER
·
2020
·
IF 4.231
Haoji Lao,Nafeesa Mushtaq,Guofei Chen,Hongyu Jiang,Yang Jiao,Anjiang Zhang,Xingzhong Fang
Two series of optically transparent polyamide-imides (PAIs) were prepared by copolymerization of trimelletic acid chloride (TMAc), p -phthaloyl chloride (TPC), 2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diamine (TFDB) and 4,4’-(9-fluorenylidene) diamine (FDA). These series of PAIs displayed high glass transition temperatures ( T g s) ranging from 340 to 441 °C, 5% weight loss temperatures ( T 5% s) in nitrogen with 459–505 °C, and low coefficient of thermal expansion (CTE) of 21–56 ppm/K, which greatly affected by the feed ratio of rigid TPC units and cardo diamine in the polymer main chain. The transmittances at 500 nm (T 500nm ) of the PAI films were found in the range of 70.0–87.7%, All polymers demonstrated good organosolubility and mechanical properties with tensile strengths of 77–146 MPa, tensile moduli of 2.9–5.8 GPa and elongations at break of 2.9–8.2%. PAI-7-8 presented the best combination of high T g of 401 °C and high tensile modulus of 5.0 GPa, low CTE value of 24 ppm/K, and high transparency (T 500nm ) of 87.2%.
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JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
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2020
·Vol. 24
·期 08
·1038-1046
·
IF 1.816
Zengduo Cui,Xin Wang,Jiale Ding,Yunhe Zhang,Zhenhua Jiang,Xuefeng Li
To enhance the nonlinear optical properties of graphene oxide in organic solvent and polymeric matrix, lutecium phthalocyanines (LuPc) and hyperbranched lutecium phthalocyanines (HBLuPc) have been grafted on the surface of graphene oxide, respectively. After the surficial modification, the electron transfer process between phthalocyanines and graphene oxide has been also facilitated, resulting in significant fluorescence quenching. Given the combination of nonlinear scattering, two-photon absorption with reverse saturable absorption and the photo-induced electron or energy transfer from the electron donor (phthalocyanine moiety) to the acceptor (graphene oxide), stronger nonlinear optical properties can be realized based on graphene oxide hybrids compared with graphene oxide and phthalocyanines. Furthermore, graphene oxide hybrid modified by hyperbranched lutecium phthalocyanines exhibits the best optical limiting response and the highest nonlinear extinction coefficient at 532 nm in both organic solvent and polymeric matrix. Interestingly, we also find that it could exhibit better optical limiting properties than those possessed by pure phthalocyanine at 1064 nm.
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JOURNAL OF CONTROLLED RELEASE
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2020
·
IF 7.727
Zhihao Guo,Junhui Sui,Mengcheng Ma,Jianshe Hu,Yong Sun,Liqun Yang,Yujiang Fan,Xingdong Zhang
Stimuli-responsive nanotechnology-mediated drug co-delivery system is a notable strategy to improve access of the systemically administered chemotherapeutics to the tumors. Herein, a tailor-made 2,3-dimethylmaleic-anhydride-poly(ethylene glycol)- ε -poly- l -lysine-doxorubicin /lapatinib polymeric nanoplatform (DMMA-P-DOX/LAP) for synergistically eliminating breast cancer is developed by encapsulating lapatinib into dual-pH responsive charge switchable biopolymer-doxorubicin conjugate nanoparticles . The physicochemical properties of polymeric nanoparticles are conducive to their stable circulation in the physiological condition, but reverse the surface charge from negative to positive ultrasensitively in slightly acidic tumor microenvironment , facilitating cell internalization and deep tumor penetration. Subsequently, DOX and LAP are synchronously released into the cytoplasm in response to the significantly increased acidity of intracellular environment. As a result, the combination therapy by DMMA-P-DOX/LAP nanoparticles compels the solid tumors to contract significantly or even vanish completely in the MCF-7 tumor model, moreover, the structural composition with amino acid and bioinert PEG ensures the favorable biosecurity of the co-delivery system in vivo . This dual-pH responsive nanotechnology-mediated drug co-delivery system provides great potentials for safe and effective cancer therapy.
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PubMed
高影响因子
Analytical Methods
·
2020
·Vol. 12
·期 21
·2727-2734
·
IF 2.596
Yuhong Zhou,Qian Liang,Zhilun Zhang,Zhaodi Wang,Mingxian Huang
A hybrid silica monolith containing vinyl groups was synthesized by a sol–gel method, and then ground and treated, yielding silica particles with a 3–5 μm particle size and a 10–20 nm pore size. Cellulose derivatives containing 3,5-dimethylphenylcarbamate groups and methacrylate groups regioselectively were then immobilized onto the surface of the above particles by the thiol–ene click reaction using an alkanedithiol as the crosslinking agent, thus forming a solvent-resisting crosslinked network structure attached onto the surface of the particles. The immobilization degree was more than 80%, and the back pressure of the chiral stationary phase (CSP) packed column was relatively low and was maintained at around 3.0 MPa. The as-prepared CSPs were shown to be able to effectively separate various enantiomers with different mobile phases.
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PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2020
·Vol. 38
·期 8
·840-846
·
IF 3.154
Hao Fu-Yao,Wang Jian-Hua,Qi Sheng-Li,Tian Guo-Feng,Wu De-Zhen
A series of polyimide (PI) films derived from pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) were prepared with the employment of chemical pre-imidization, and the pre-imidization degree (pre-ID) was found influential on structures and properties of the films obtained. Specifically, a certain degree of chemical imidization could promote the in-plane orientation of molecular chains inside the film, which then enhanced the mechanical strength and reduced the coefficient of thermal expansion (CTE) of the films. Further, such pre-imidization process could expand the internal space gap inside the films, thereby lowering their dielectric constant and glass transition temperature. Our study provides a new approach for preparing high-performance PI films through chemical imidization.
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JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Shuyun Zhu,Zhenjia Zheng,Hongwei Peng,Jing Sun,Xian-En Zhao,Huwei Liu
This work proposed a novel strategy based on quadruplex stable isotope derivatization for sensitive, accurate, speedy and green determination of panaxadiol (PD) and panaxatriol (PT). This strategy integrated with ultrasound-assisted dispersive liquid-liquid microextraction, microwave-assisted derivatization, and magnetic graphene oxide dispersive solid phase extraction as efficient sample pretreatment techniques, coupling with ultra-high performance liquid chromatography tandem mass spectrometry detection in multiple reaction monitoring mode for the analytical purpose of high-throughput, sensitivity, selectivity, green and accuracy. Quadruplex mass spectrometry sensitizing derivatization reagents, 3- N -( D 0 -/ D 3 -methyl-, and D 0 -/ D 5 -ethyl-)-2′-carboxyl chloride rhodamine 6 G, were designed, synthesized and applied for the high-throughput derivatization of hydroxyl‑containing PD and PT for the first time. The analogue derivatives of PD and PT standards using 3- N -propyl-2′-carboxyl chloride rhodamine 6 G as derivatization reagent were employed as the internal standards for the mass spectrometry quantitation to minimize matrix effect. All rhodamine 6 G derivatives of PD and PT were easily and selectively adsorbed by magnetic graphene oxide for efficient magnetic dispersive solid phase extraction before injection. Parameters of (micro-) extractions, derivatization and liquid chromatography-mass spectrometry conditions were all optimized in details. Method validation results consisting of linearity, accuracy, precision, repeatability, matrix effect, stability and limits of detection (LODs, 0.02 ng/mL for PD and 0.03 ng/mL for PT) were determined. The analytical performance of this method benefited from efficient integration of suitable sample pretreatment techniques and characteristic structure of rhodamine 6 G with four mass tags in derivatization reagents. The developed and validated method has been applied to the quantitation of PD and PT for the quality assessment of related foodstuffs and traditional Chinese medicinal materials.
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高影响因子
Polymers
·
2019
·Vol. 11
·期 12
·2048
·
IF 3.164
Qinrui Zhu,Dagang Li
Interface optimization in preparing natural fiber based biocomposite becomes a key factor that determines overall properties, especially mechanical performance. The solution for upgrading interfacial adhesion stemmed from polar fiber and nonpolar polymer remains unclear. Here, a kind of pulp fiber/acrylonitrile-butadiene-styrene (ABS) composite with content ratio of 1:1 was fabricated by functionalizing the cellulose fiber to coordinate interaction between fiber and ABS. With addition of 5 wt % polyacrylamide (PAM) there existed an interlinked three-element structure in composite. Three types of treatment to cellulose fiber, including alkali immersion, pivaloyl chloride grafting for 10 h and 20 h were conducted. Pulp fiber that was treated with alkali for one hour, followed by pivaloyl chloride reaction for ten hours, proved to be effective for interfacial adhesion. X-ray Photoelectron Spectroscopy (XPS) analysis reveals 21.9% of carbonyl and 12.1% of ester function in this fiber, which corresponds to oxidation and grafting. For its composite SEM picture displays that most of cellulose fiber are rooted in ABS and evident traces of tearing or fracture can be observed after tension test. DMA test indicates that this modified pulp fiber/ABS composite exhibits great compatibility, because of combined loss modulus peak ranging from 80 °C to 100 °C. Moreover, the well miscible composite has a tensile strength of 58.1 MPa and elastic modulus of 2515 MPa, increasing by nearly 50% and 60% from those of pure ABS, respectively.Keywords:ABS;modification;interfacial adhesion;compatibility;interlinked structure
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2019
·
IF 4.527
You Zhou,De-Qiang Qin,Pei-Wen Zhang,Ben-Ju Liu,Xiao-Tian Chen,Zhi-Xiang Zhang
Azadirachtin , as the most promising and effective botanical insecticide, exhibits significant growth inhibition activity against agricultural and forestry pests. However, its biochemical effects at the metabolic level compared with those of other insect growth regulators have not been studied. Therefore, in this study, a GC–MS based untargeted metabolomics approach was applied to compare azadirachtin with pyriproxyfen (a juvenile hormone analog) and tebufenozide (a molting hormone analog) in terms of their metabolic effects on Bactrocera dorsalis larvae. The bioactivity of azadirachtin against B. dorsalis larvae was significantly different than those of pyriproxyfen and tebufenozide. A total of 693 mass features were recognized, and 112 metabolites were identified in this study. The results showed that a total of 16, 13 and 10 differentially regulated metabolites corresponding to 12, 5 and 8 pathways occur in Aza versus CK, Pyr versus CK and Teb versus CK group, respectively. Further analysis showed that 6 differentially regulated metabolites corresponding to 5 key pathways could be the primary differential metabolic response of B. dorsalis larvae to the three insect growth regulators. The pathways were myo-inositol corresponding to ascorbate and aldarate metabolism as the specific response of B. dorsalis larvae to azadirachtin; xylitol, xylulose and 3-aminopropionitrile corresponding to pentose and glucuronate interconversions, and cyanoamino acid metabolism as the common responses to azadirachtin and pyriproxyfen; and 3-hydroxypropionic acid and beta-alanine corresponding to propanoate metabolism and beta-alanine metabolism as the specific responses to tebufenozide. The results showed that the metabolic response of B. dorsalis larvae to azadirachitin is closer to that of pyriproxyfen than tebufenozide. The differentially regulated metabolites and pathways responsible for this difference are discussed.
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Polymer Chemistry
·
2019
·Vol. 11
·期 4
·810-819
·
IF 4.76
Akram Yasin,Yurong Chen,Yanxia Liu,Letao Zhang,Xingjie Zan,Yagang Zhang
Different from traditional polyethylenimine (PEI) modified Hg(II) adsorbent materials, a novel hyperbranched polythioamide adsorbent (SPD) was prepared by using sulfur, PEI and 1,4-diethynylbenzene (DEB) as monomers. There are tens and thousands of tons of sulfur produced from oil refinery processes as a major by-product each year, and its utilization becomes a concern due to its limited consumption, environmental problems and safety. Herein, a SPD was fabricated through a one-pot, catalyst-free polymerization which even can be solvent-free via using sulfur to solidify the liquid PEI. A kinetic study showed that the adsorption of Hg(II) ions followed the pseudo-second-order model, indicating chemical adsorption between Hg(II) ions and SPD. The SPD had a maximum adsorption capacity of 1161.99 mg g−1. FT-IR and XPS measurements indicated that the removal of Hg(II) by SPD was mainly controlled by the coordination interaction between Hg(II) ions and nitrogen groups (i.e., amine and imine groups), and also CS bonds of SPD. By using elemental sulfur, PEI becomes the backbone of the polymer system by forming –C(S)NH– and –C(S)N< groups unlike the grafted part of traditional PEI modified materials. TG, DTG, and DSC measurements showed that the main degradations occurred at around 160 °C and 360 °C.
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Agriculture-Basel
·
2019
·Vol. 9
·期 12
·250
·
IF 0
Hua Huang,Yueming Jiang
This study comprehensively analysed the chemical composition of the cuticle in pitaya fruits. The total coverage amount of the waxes versus cutin monomers accumulated at a ratio of 0.6, corresponding to masses per unit of 30.3 μg·cm−2and 50.8 μg·cm−2, respectively. The predominant wax mixtures weren-alkanes in homologous series of C20–C35, dominated by C31and C33; as well as triterpenoids with an abundant amount of uvaol, lupenon, β-amyrinon, and β-amyrin. The most prominent cutin compounds were C16- and C18-type monomers, in which 9(10),16-diOH-hexadecanoic acid and 9,10-epoxy-ω-OH-octadecanoic acid predominated, respectively. The average chain length (ACL) of aliphates in pitaya fruit cuticle (30.5) was similar to that estimated in leaf waxes, and higher than that in most of the fruit and petal waxes that have been reported. We propose that the relatively high ACL and wax/cutin ratio might enhance the cuticular barrier properties in pitaya fruit cuticle to withstand drought.Keywords:pitaya fruit;cuticle;wax;cutin;ACL
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Journal of Physical Chemistry C
·
2019
·
IF 4.309
Qinghua Deng,Yun Xu,Ziqun Wang,Tifang Miao,Xianliang Fu,Liancai Xu
The development of new catalysts based on nonprecious metals for photocatalytic H2 evolution reaction (HER) is a very challenging endeavor. In this work, we used density functional theory (DFT) to design a high performance photocatalyst based on CoIII(dmgH)2pyCl. The sample was then prepared and used for photocatalytic HER under visible light irradiation with Eosin-Y (EY2–) and triethanolamine (TEOA) as a photosensitizer and electron donor, respectively. The feasibility and rationality of the DFT design were verified by the consistency between the photocatalytic performances and the theoretical results. The developed catalyst even showed the capability of splitting of water for H2 evolution. As for the most promising CoIII(dmgH)2(pyrazine)Cl, 1356 μmol of H2 can be produced over 25 mg of catalyst after irradiation for 3 h. The deactivation and the mechanism for the evolution of H2 over the sample were further investigated. We believe that this study provides an effective strategy for the design of highly efficient photocatalysts for HER.
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